<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<script>
/*
 if(表达式){
 //代码
 }
 
 if(表达式){
 //
 }else{
 //
 }
 
 if(条件){
 
 }else if(条件){
 
 }....
 else{
 }
 */
/*var score = parseFloat(prompt("请输入学生的成绩"))
 if (score >= 90){
 console.log("优秀");
 }else if (score >= 80){
 console.log("良好")
 }else if (score >= 70){
 console.log("一般")
 }else if (score >= 60){
 console.log("及格")
 }else{
 console.log("不及格");
 }*/
var num1 = 50;
var num2 = 30;
var num3 = 250;
var max;
/*if (num1 > num2){
    if (num1 > num3){
        max = num1;
    }else{
        max = num3
    }
}else{
    if (num2 > num3){
        max = num2;
    }else{
        max = num3
    }
}*/
if(num1 > num2 && num1 > num3){
    max = num1;
}else if(num2 > num1 && num2 > num3){
    max = num2;
}else{
    max = num3
}

console.log("最大值是:" + max);
</script>
</body>
</html>